Snobs and slobs: Ants are just like us

ASU animal behavior researcher finds that tree-anchored colonies in Panama display different personalities from their neighbors

You’re at your front door, engaged in the universal human pastime of judging the neighbors.

There’s Perfect Guy. His lawn looks like a flawless green carpet. His wood pile could pass Marine inspection. Your place is never going to look that good.

Then there’s The Slob, with the blue tarp over the carport and a car perched on blocks for years.

You and your neighbors, as it turns out, have a lot in common with ants — according to a recently published study by an Arizona State University animal behavior researcher.

Azteca ant colonies live in Cecropia trees, defending the trees from threats like choking vines and leaf-eaters. But some ants are more active in defending their tree homes than others, revealing that colonies themselves have personalities.

Peter Marting, a doctoral candidate in animal behavior in the School of Life Sciences, discovered that trees with more active, aggressive colonies have less leaf damage, suggesting that colony personality plays an important role in the mutually beneficent relationship between ant and tree.

“There are inherent, consistent differences from one colony in this tree versus one colony down the street in that tree. You could see it even without officially quantifying it,” Marting said. “... This colony just doesn’t respond to anything; they’re being very cautious and reserved about what they respond to. It’s hard to measure their intent, whether it’s caution or apathy or what it actually is. ... Other colonies are just full-throttle.”

Video of Ant Plants: Cecropia - Azteca Symbiosis

Video by Pratt Lab

In the lowland tropical rainforests of Soberanía National Park in Panama, Marting studied five types of behavior: patrolling behavior, vibrational disturbance, response to intruders, response to leaf damage and exploratory tendency.

The study of animal personalities, or behavioral syndrome, is relatively new. The term was coined in a 2004 paper by biologist Andy Sih of the University of California, Davis.

“He pointed out that the field of behavior, in many fields, tend to look at the population average — take what everybody is doing and take the average — and say something about this population versus that population, and not exploring that variation,” Marting said. “Let’s say I take the mean of these ants I just studied, like the mean aggression level. I would be completely losing all this really valuable information about individuality. What’s up with this variation? Where does it come from? What are the consequences of having a certain personality type?”

Some animals will take an aggressive, bold approach, and others will be more cautious and reserved. There is a world of variation going on among them.

“That really opened up a lot of people’s eyes,” Marting said. “I think one of the things that’s really attractive about that concept in this field is that we interact with that conceptual framework on a day-to-day basis with the humans that we know. We’re judging personality all the time. This person has this, that person has that. It’s just something that’s so inherent to our everyday experience. ... It opens up the animal world in terms of thinking about their existence. ... I think that sparks a lot of interested researchers — certainly myself — in thinking about ‘OK, wow, I really want to know why is this bird like that and why is that bird like this?’”

Think about pets you’ve owned that had different personalities, regardless of breed. The same thing goes on in the wild. The advantage we have in observing this behavior in pets is we spend every day with them. It’s tough to study in the wild.

An Azteca ant peeks from a Cecropia tree in Soberanía National Park, Panama.

Photo courtesy of Peter Marting

The Cecropia tree canopy in the Soberanía National Park. Each tree will host an Azteca ant colony, providing shelter and food to the ants. In return, the ants protect the tree by fending off animal intruders such as herbivores and attacking invasive plant species that encroach on the tree.

Photo courtesy of Peter Marting

Azteca ant workers attack an encroaching vine on a Cecropia tree.

Photo courtesy of Peter Marting

Peter Marting, a doctoral candidate in animal behavior in the School of Life Sciences, studied five types of behavior — patrolling behavior, vibrational disturbance, response to intruders, response to leaf damage, and exploratory tendency — in the lowland tropical rainforests of Soberanía National Park in Panama.

Photo courtesy of Peter Marting

Azteca ant colonies have personalities: Some are more active in defending their tree homes than others.

Photo courtesy of Peter Marting

“With wild animals, we see one individual, once,” Marting said. “If you’re able to track wild animals and measure their behavior repeatedly in the wild, you get to reveal these personalities that exist. It’s really hard to do in the wild, so there are very few studies which have shown behavioral syndromes in ecological context in nature. The study system I’m using here with the ants that are locked in the trees — those trees aren’t going anywhere; colonies don’t move — I have a huge advantage in being able to roll right up to these trees and look at it for months or years.”

“I think anthropomorphism is something you should be cautious about,” he said. “It’s also kind of a nice tool sometimes to open up different aspects of an animal’s existence that you can explore. I’m not as cautious as most biologists about anthropomorphizing. I think it can be a good tool to understand or get a story across. It should always be explored or backed up by research. I tend to be a little loose with it myself.”

He pointed to grackles hunting for crumbs on the Starbucks patio where he was sitting for an interview.

“These grackles right here — there’s probably all kinds of different personalities, and those personalities are interacting, and they have friends, if you would, interacting with some more than others. There’s this whole world of variation going on.”

Three follow-up papers by Marting are coming along. “Colony personality and plant health in the Azteca-Cecropia mutualism” was published in November in Behavioral Ecology.

Scott Seckel

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Arizona State University has been awarded a $380,000 grant from the Andrew W. Mellon Foundation for a three-year implementation project to reinvent the library’s strategy and practice for open-stack print collections. The work will enable ASU Library to design and develop inclusive library print collections for ASU Library to engage, educate and inspire scholars and learners of the ASU community...

Arizona State University has been awarded a $380,000 grant from the Andrew W. Mellon Foundation for a three-year implementation project to reinvent the library’s strategy and practice for open-stack print collections. The work will enable ASU Library to design and develop inclusive library print collections for ASU Library to engage, educate and inspire scholars and learners of the ASU community.

Under the leadership of University Librarian Jim O’Donnell and Associate University Librarian for Collections and Strategy Lorrie McAllister, the project — titled “The Future of the Arizona State University Library Print Collection: A Collaborative and Data-driven Approach to Stack Design and Curation” — follows a yearlong planning process, supported by the Mellon Foundation, in which ASU Library identified issues and options affecting the design of the next generation of open-stack print collection for a research library. Photo by Charlie Leight/ASU NowDownload Full Image

As libraries adapt to new pathways for organizing information and access in the digital age, institutions face the important challenge of preserving print collections in ways that best serve the public. What becomes of the print collection that users see on open shelves in an age when more and more of libraries’ collections are shelved offsite?

Rather than viewing these new forms of access as a threat to print, ASU Library recognizes a vital opportunity to leverage the design and curation practices in ways that engage a broader spectrum of students and scholars in new ways.

“All the scholarly work of the last generation on the history of the book has shown that physical books have always had many functions and complex social dimensions,” said O’Donnell, principal investigator. “Reading a print volume closely and attentively remains a powerful practice for learning and research at every level, but flipping the pages of a print volume in slightly more than idle curiosity remains powerful as well. Print volumes give visibility and visual character to the past and present artifacts of culture. If ‘out of sight, out of mind’ is a true-enough proverb, then what is in sight will be what is in mind — and we can control that in our libraries. How can we best shape the experience of our users in approaching our libraries by the resourceful use of print?”

“ASU is committed to serving a diverse student body and fostering a community wherein the accessibility of education is a guarantee,” said ASU President Michael M. Crow. “We look for ways to unlock access to knowledge and information for the broadest cross-section of students in our community, who in turn reflect the diversity of our surrounding communities. This project will not only create a sustainable model for ASU’s print collections lasting into the future, but it will also extend the depth and breadth of our students’ access to information literacy and tools for independent inquiry.”

The vision for revitalizing public engagement with print comes at a key moment in the university’s plans to renovate its largest library — Hayden Library — and grow student enrollment to 200,000 by the year 2025. As a result, ASU Library must rethink every aspect of its services in order to innovate and scale support for scholars and learners who come from a variety of backgrounds and take many approaches to their education.

“Traditional library practices often indicate the retention of books in open stacks according to highest circulation, English language and authors recognized as being part of the mainstream. ASU seeks to create a local collection designed to inspire and engage our users with more inclusive collections that more accurately reflect the user populations within ASU and our surrounding communities,” said McAllister, co-principal investigator. “We aim to keep our open-stack collections as active, living, growing entities. The books our students see on our shelves should not be treated as furniture, wallpaper or relics not to be touched and used, but as a vital set of tools of sustaining value for the future.”